KR100525583B1 - An aqueous paint coating composition, a process for inhibiting the discoloration of dry film of a pyrithione-containing paint coating composition due to ultraviolet light degradation, a process for removing the discoloration in an aqueous antimicrobial paint composition, an aqueous antimicrobial coating composition for water-based paints, adhesives, caulks and sealants, and a substrate coated with an aqueous coating composition - Google Patents

Abstract

The present invention is selected from (a) water, (b) base medium, (c) 0.01 to 2.0% by weight of pyrithione salt based on the total weight of the coating composition, and (d) many grades suitable for paint production. It relates to an aqueous coating composition comprising a zinc oxide compound at a concentration of 0.001 to 10% by weight, based on the total weight of the composition. The present invention is also intended for substrates selected from the group consisting of aqueous paints, adhesives, cokes, sealants and combinations thereof, comprising water, pyrithione salts or pyritic acids, organic base media and zinc compounds and coated with zinc ions. An aqueous antimicrobial coating composition having antifungal efficacy and protecting against discoloration due to the presence of pyrithione, which is present in the composition in an amount of 0.001 to 10% by weight, based on the total weight of the composition.

Description

Aqueous paint coating compositions, methods of inhibiting discoloration of dry films of pyrithione-containing paint coating compositions due to ultraviolet photolysis, methods of removing discoloration of aqueous antimicrobial paint compositions, aqueous ports for aqueous paints, adhesives, cokes and sealants An aqueous paint coating composition, a process for inhibiting the discoloration of dry film of a pyrithione-containing paint coating composition due to ultraviolet light degradation, a process for removing the discoloration in an aqueous antimicrobial paint composition, an aqueous antimicrobial coating composition for water-based paints, adhesives, caulks and sealants, and a substrate coated with an aqueous coating composition}

The present invention relates generally to coating compositions, and more particularly to coating compositions in the form of anhydrous films on a substrate, characterized by enhanced antimicrobial efficacy and resistance to discoloration, both in wet and after drying.

Pyrithione is a well known antimicrobial additive useful in many applications. Sodium pyrithione (also called sodium salt of 1-hydroxy-2-pyridinthion, sodium pyridine-2-thiol-N-oxide or 2-pyridinethiol-1-oxide, Na salt) has excellent antimicrobial properties. It is one of pyrithione salts and is typically used as fungicides and preservatives in functional fluids such as metalworking fluids, lubricants, cosmetics and toiletries. Sodium pyrithione is a well known product, generally prepared by reacting 2-chloropyridine-N-oxide with NaSH and NaOH as described, for example, in US Pat. No. 3,159,640.

Likewise, zinc pyrithione (also known as zinc pyridine-2-thiol-N-oxide or bis [1-hydroxy-2 (H) pyridineethionato] zinc]) is a good antimicrobial additive. Zinc pyrithione is reacted with 1-hydroxy-2-pyridinethione or a soluble salt thereof and a zinc salt (eg ZnSO ₄ ) to form zinc pyrithione precipitates, as described, for example, in US Pat. No. 2,809,971. Can be prepared. Zinc pyrithione is used as a broad antimicrobial and preservative in metalworking fluids, plastics, paints, adhesives and cosmetics. Its important uses include as anti-dandruff in hair products, as preservatives in various cosmetics and as antifouling agents in marine paints. The commercial use of zinc pyrithione in paints, adhesives, caulks and sealants is increasing.

In the presence of iron ions, sodium or zinc pyrithione-containing compositions tend to be blue, although much less than when iron ions are present, even when only a small amount of iron ions are present. Similarly, photolysis of pyrithione moieties can occur in the presence of natural light, i.e. ultraviolet radiation, which is a component of outdoor light. The blue or yellowing is undesirable for aesthetic reasons as well as for functional reasons relating to unwanted color formulations.

The aesthetics of paints, adhesives, cokes and sealants typically require certain desired colors after they are dried to form a dry coating on the substrate and are required for the manufacturer of the product to take a long time to achieve a particular color effect. Any component that changes the white or color of the formulation can make the task of the coloring manufacturer very difficult. For example, when formulating aqueous paints, paint bases (such as partially formulated paints prior to pigment addition), adhesives, cokes and sealants, any unwanted color in the additives adversely affects the color of the formulated product. The discoloration typically has an adverse effect on the desired product color to produce a faded product.

In addition, yellowing of the dry film on the substrate by exposure to ultraviolet light ("UV"), which is a natural outdoor light component, adversely affects the paint from two viewpoints. First, yellowing of the paint becomes aesthetic problem because the color of the paint changes immediately upon exposure to UV. Secondly, pyrithione photolysis by UV exposure reduces the amount of pyrithione useful for protecting the paint film.

In the past, various solutions to the hearing problem have been proposed. For example, US Pat. Nos. 4,957,658 and 4,818,436 describe the addition of alkali metal salts or alkaline earth metal salts of 1-hydroxyethane-1,1-diphosphonic acid to paint or functional fluids, such as metalworking fluids, respectively. A solution to the discoloration problem discussed above in paints and functional fluids due to the simultaneous presence of iron ions and pyrithione is described. Although US Pat. Nos. 4,957,658 and 4,818,436 suggest good solutions to discoloration, these solutions are not always cheap or permanent as desired.

As another example, US Pat. No. 4,161,526 discloses white to pale yellow pyrithione for application to the skin or hair, containing from about 0.01 to about 1% of zinc salts, zinc hydroxide or zinc oxide or mixtures of organic carboxylic or inorganic acids. , Pyrithione salts or dipyrithione are described. The compositions of US Pat. No. 4,161,526 are known to be effective in preventing or eliminating discoloration caused by the formation of colored pyrithione, pyrithione salts, or dipyrithione contaminants (referred to as iron pyrithione) in the composition. U. S. Patent No. 4,161, 526 does not teach a solution to the problem of discoloration in compositions that are independent of skin or hair protection and contain no iron pyrithione.

In addition to discoloration issues, unwanted ions such as iron ions can cause functional problems with the antimicrobial performance of pyrithione. The inventors have found that the performance problem is that pyrithione tends to form a blue precipitate in the presence of iron ions and that precipitation of pyrithione lowers its bactericidal protection by reducing the amount of pyrithione available throughout the composition. It is believed to come from.

Moreover, the inventors have found that the presence of large amounts of zinc oxide in pyrithione-containing paints can inhibit the short-term (early stage) antimicrobial efficacy imparted to the paint by pyrithione when dried to form anhydrous films on the substrate. Said that. This reduced short-term potency adversely affects paint function, in particular, the paint film's resistance to mold growth.

There is a great need for new solutions to the yellowing, blue and greening problems in various pyrithione-containing aqueous coating compositions, especially paints, adhesives, cokes and sealants. The preferred solution is that pyrithione can be used in coating compositions containing iron or copper without any discoloration in the coating composition, which is cheaper, longer in life and lasting than required in the prior art discussed above. And / or using lower concentrations of additives. Particularly preferred solutions, ie solutions that provide improved short and long term antimicrobial resistance of coating compositions and resulting coatings against microbial attack, are highly desired in the field of manufacturing paints, adhesives, cokes and sealants. The present invention provides one of the above solutions.

In one aspect, the invention provides a composition comprising a) water, b) a base medium, c) 0.01 to 2.0% pyrithione salt based on the total weight of the composition and d) 0.001 to 10% based on the total weight of the composition. An aqueous coating composition comprising a zinc oxide compound selected from many grades suitable for paint production at a concentration. Typical coating compositions include aqueous compositions of paints, adhesives, cokes, sealants, latex emulsions, pigment slurries, patching compounds, bonding mixtures or concrete mixtures.

In another aspect, the present invention includes incorporating a zinc compound selected from the group consisting of zinc salts of organic acids, zinc salts of inorganic acids, zinc hydroxide, zinc oxide and combinations thereof into an effective amount coating composition, thereby ultraviolet photolysis of pyrithione. A method of suppressing anhydrous film-discoloration of a pyrithione-containing coating composition due to

In another aspect, the present invention provides an aqueous antimicrobial composition containing dissolved metal ions selected from the group consisting of iron ions, copper ions, and combinations thereof, in an amount greater than or equal to the amount of metal ions dissolved in the composition. To a method for removing undesired discoloration of the composition, including contacting with zinc ions.

In yet another aspect, the invention relates to an aqueous antimicrobial coating composition, characterized by antifungal efficacy and protected against discoloration due to the presence of pyrithione contained, wherein the composition comprises an aqueous paint, adhesive, coke and For a substrate selected from the group consisting of sealants and combinations thereof, the composition comprises water, a pyrithione salt or acid, an organic base medium and a zinc compound, wherein zinc ions are from 0.001 to 0.001 based on the total weight of the coating composition. Present in the composition in an amount of 10%.

In another aspect, the invention relates to a coated substrate comprising a substrate selected from the group consisting of wood, metal, plastic substrates and mixed materials thereof and a coating on the substrate, wherein the coating is a zinc salt of pyrithione and an organic acid, Zinc compounds selected from the group consisting of zinc salts of inorganic acids, zinc hydroxide, zinc oxide and combinations thereof.

These and other aspects will be apparent from the following detailed description of the invention.

Surprisingly, in the present invention, a zinc compound (such as zinc salt, zinc oxide or zinc hydroxide) is formulated in a coating composition together with a pyrithione compound (preferably zinc pyrithione) and applied to the substrate for coating composition. It has been found that an advantageous combination of antimicrobial (particularly antifungal) efficacy and resistance to UV attack is provided for the dry anhydrous coating.

It has also been surprisingly found that, according to the present invention, zinc can be added to a composition containing pyrithione and iron or copper ions to reduce or avoid discoloration problems caused by the composition. Without being bound by any particular theory, there are a number of potential causes for discoloration problems. For example, the presence of undesirable ions in tap water and filler components (such as iron ions) in coating compositions not only discolor the composition, but also insoluble iron pyrithione precipitates that deplete pyrithione useful for sodium pyrithione-containing compositions. To reduce the antimicrobial efficacy of the composition.

In addition, ultraviolet light, which is a natural outdoor light component, tends to cause yellowing of the anhydrous-film coating containing pyrithione. According to the present invention, the presence of zinc oxide in the preferred range of 0.02 to 0.5% by weight, based on the total weight of the coating composition, in the pyrithione-containing coating composition is characterized by the antimicrobial efficacy of the coating composition and undesirable blue or other discoloration. It has been found that it is possible to avoid the undesirable yellowing or other discoloration of the anhydrous film obtained by coating the substrate with the coating composition.

The term "discoloration" as used herein for pyrithione containing coating compositions refers to some unacceptable gray, blue, black, purple, green or other colors other than the natural or desired artificial color of the paint or paint base formulation. It is intended to describe. The term "discoloration" is also intended to describe any yellowing or browning of the anhydrous film obtained by coating the substrate with a coating composition. The yellowing or browning typically occurs by photolysis of pyrithione in the coating.

Discoloration of the coating composition may be due to unwanted metal ions (eg iron or copper) incorporated in the coating composition from the starting materials used in the preparation of the coating composition. Typical starting materials include sources of pyrithione in the form of sodium pyrithione, zinc pyrithione and combinations thereof, as well as tap water and fillers (such as calcium carbonate) used to prepare coating compositions. For example, the natural color of sodium pyrithione itself is transparent yellow. However, it is very common for iron and / or copper contaminants to be introduced into an aqueous composition from the tap or filler used to prepare the coating composition to cause discoloration of the composition. One way to quantify the degree of discoloration is to measure color reflection parameters and calculate white values from them. Another method is to visually examine the composition for signs of graying compared to the desired color or white.

In aqueous paints, adhesives, cokes and sealants, significant concentrations of iron or copper ionic impurities in amounts greater than 250 ppm are common. By incorporating an effective amount of zinc salts, zinc hydroxide or zinc oxide, or mixtures of organic or inorganic acids into the composition, the typical blue coloration due to the presence of iron ions bound to pyrithione is moderately reduced, such as greening due to the presence of copper ions. , Eliminated or avoided.

The amount of the zinc salt, zinc hydroxide or zinc oxide or combinations thereof described above, required for preventing discoloration in the anhydrous film produced by coating the substrate with the coating composition and in the coating composition in which they are used is And may range from 0.001 to 10% by weight (preferably 0.001 to 3%, more advantageously 0.02 to 0.5% by weight) based on the total weight of the coating composition in which they are used.

When using zinc oxide, the amount of zinc oxide should preferably not exceed 0.5% by weight, based on the total weight of the coating composition, to provide an advantageous blend with short and long term antimicrobial efficacy in anhydrous films. (Advantageously, 0.002 to 0.2 wt%) has been found in the present invention. If it exceeds 0.5% by weight, there is a risk that zinc oxide inhibits the short-term efficacy of zinc pyrithione in anhydrous films due to the well-known "common ionic effect" due to zinc present in both of these components. The "common ionic effect" means that when all zinc ions, pyrithione ions, and non-ionized zinc pyrithione are present in the composition, they force equilibrium with non-ionized zinc pyrithione, leaving these components in non-ionized form. As long as the antimicrobial efficacy of zinc pyrithione is suppressed.

If desired, the pyrithione used in the methods and compositions of the present invention, although pyritic acid may be used, is preferably a pyrithione salt (e.g. sodium pyrithione, zinc pyrithione, chitosan pyrithione and magnesium disulfide pyrithione, etc.). to be. More preferred pyrithione salts include sodium pyrithione and zinc pyrithione, most preferably zinc pyrithione.

Sodium pyrithione useful in the present invention is a well known commercial product, generally prepared by reacting 2-chloropyridine-N-oxide with NaSH and NaOH as described in US Pat. No. 3,159,640.

Zinc pyrithione is a zinc pyrithione precipitate by reacting 1-hydroxy-2-pyridinethione (eg pyrithiate) or a soluble salt thereof with a zinc salt (eg ZnSO ₄ ) as described in US Pat. No. 2,809,971. It can be prepared by forming a.

Aqueous compositions of the present invention are incorporated into or onto plastics or fabrics or nonwovens when formulated to be suitable for a variety of uses, for example soaps, shampoos, skin care drugs, paints or to contain antimicrobial ingredients as well as necessary ingredients. do.

The antimicrobial compositions of the invention are particularly useful in the form of paints, including indoor and outdoor paints, industrial and commercial paints. In addition, the antimicrobial compositions provide desirable results when the antimicrobial components are incorporated into latex type outdoor paints.

The coating composition of the present invention is suitably applied to a substrate such as a wood, plastic or metal substrate and dried to form an anhydrous coating.

Anhydrous films formed by coating the coating composition of the present invention onto a substrate and drying exhibit excellent resistance to the growth of mold and algae as indicated by outdoor exposure tests using plates painted with the coating composition. However, certain paint formulations, i.e., formulations rich in hydrophilic components, can provide a more favorable environment for both mold and algal growth than the coatings tested. Fungi need water to survive. The hydrophilic material in the paint film keeps the wettability of the film high. This provides a better environment for mold and can also lead to accelerated leaching of hydrophilic materials. The hydrophilic components in these formulations tend to cause relatively soluble antimicrobial additives to leach out of the formulation, providing good short term antimicrobial protection at the expense of long term antimicrobial protection due to this leaching effect. Under such circumstances, using zinc pyrithione, a relatively water-insoluble antimicrobial additive in combination with a relatively water-soluble antimicrobial additive in accordance with the present invention, anhydrous paints prepared using paint formulations containing high concentrations of hydrophilic components It is believed to provide a good combination of the desired short and long term antimicrobial protection in the film. Relatively water-soluble antimicrobial agents useful as co-bactericides for anhydrous film efficacy when used in combination with zinc pyrithione according to the present invention are iodopropynyl butylcarbamate ("IPBC"), n-octyl isothiazoline- On ("OIT"), methylene thiocyanate ("MTC"), thiocyanomethylthio benzothiazole ("TCMTB"), thiazolyl benzimidazole ("TBZ"), benzimidazolyl carbamic acid methyl ester ("BCM"), triazoles such as chlorophenylethyl dimethylethyl triazole ethanol ("tebuconazole", commercially available from Bayer), substituted triazines such as tert-butylamino Cyclopropylaminomethylthio-s-triazine and dichlorophenyl dimethylurea ("Diuron", commercially available from Bayer) and combinations thereof. These auxiliary fungicides, alone or in combination with zinc pyrithione, are suitably added to the desired paint to provide a paint having a molar ratio of zinc pyrithione to auxiliary fungicide of 1:10 to 10: 1.

Typically, as is well known in the art, paint compositions contain not only antimicrobial components but also resins, pigments and various optional additives (eg thickeners and wetting agents, etc.). The resin is preferably selected from the group consisting of vinyl, alkyd, epoxy, acrylic, polyurethane and polyester resins and combinations thereof. The resin is preferably used in an amount of about 20 to about 80 weight percent based on the weight of the paint or paint base.

In addition, the paint compositions of the present invention further contain any additives which have a desirable effect on viscosity, wetting and dispersing as well as stability and foamability to freezing and electrolytes. In the manufacture of marine paints, the paints preferably contain swelling agents such that the paint gradually "sloughs off" in the seawater environment, thereby resulting in the newly exposed sterilant of the paint surface being in contact with the water medium of the seawater environment. Efficacy is restored. Exemplary swelling agents are naturally occurring or synthesized clays (eg kaolin, montmorillonite and bentonite), clay mica (battle mica) and chlorite (hectorite). In addition to clays, other swelling agents, including commercially available natural or synthetic polymers as POLYMERGELs, have been found to be useful in providing the desired "sloughing off effect". Swelling agents can be used alone or in combination. The total amount of optional additives is preferably 20% by weight or less, more preferably about 1 to about 5% by weight, based on the total weight of the paint composition.

Exemplary thickeners include cellulose 30 derivatives such as methyl, hydroxyethyl, hydroxypropyl and carboxymethyl cellulose, poly (vinyl alcohol), poly (vinylpyrrolidone), poly (ethylene glycol), poly (acrylic acid) Salts and salts of acrylic acid / acrylamide copolymers.

Suitable wetting and dispersing agents include sodium polyphosphate, salts of low molecular weight poly (acrylic acid), salts of poly (ethane sulfonic acid), salts of poly (vinyl phosphonic acid), salts of poly (maleic acid) and maleic acid with ethylene, carbon number Copolymer salts with one olefin and / or styrene of 3 to 18 are included.

In order to increase the stability to freezing and electrolytes, the paint composition may contain various monomers 1.2-diols such as glycols, propylene glycol (1.2) and butylene glycol (1.2) or polymers or ethoxylated compounds thereof, for example , Ethylene oxide and long-chain alkanols, amines, alkyd phenols, poly (propyleneglycol), or poly (butylene glycol) reaction products or combinations thereof and the like can be added.

The minimum temperature of film formation of the paint composition can be reduced by adding a solvent such as ethylene glycol, butyl glycol, ethyl glycol acetate, ethyl diglycol acetate, butyl diglycol acetate or alkylated aromatic hydrocarbons. As antifoaming agents, for example, poly (propylene glycol) and polysiloxanes are suitable. Optionally, another fungicide can be further incorporated into the paint formulation of the present invention.

The paint compositions of the present invention can be used as paints for natural or synthetic materials, such as wood, paper, metals, fibers and plastics. It is particularly suitable as outdoor paint and excellent for use as marine paint.

Another important use for the aqueous compositions of the present invention is, for example, antimicrobial components as well as latex emulsions, any rosin emulsions, any plasticizers, any antioxidants and any pigments or fillers such as calcium carbonates. It is a use as a latex tile adhesive normally containing. Another important use for the aqueous composition of the present invention is a latex coke which conventionally contains not only antimicrobial components but also acrylic latex, nonionic surfactants, dispersants, any plasticizers and any pigments or fillers such as calcium carbonate. It is used as.

Aqueous antimicrobial compositions of the present invention are useful in various applications, either alone or in combination with water, liquid hydrocarbons, ethanol, isopropanol, etc., as disinfectants and preservatives in liquid or dispersible solid forms, as described herein. They may be used to inhibit bacteria and fungi on various substrates using conventional methods and may be applied on bacterial or fungal organisms or substrates in antimicrobial amounts by conventional methods such as spraying, dipping, impregnation, and the like. have.

The invention is further illustrated by the following examples. Unless otherwise specified, "parts" and "%" are "parts by weight" and "% by weight", respectively.

Although the present invention has been described above as specific embodiments thereof, it will be apparent that many changes, modifications and variations can be made without departing from the spirit of the invention described herein. Accordingly, all such changes, modifications and variations that fall within the spirit and broad scope of the appended claims should be considered to be included in the present invention.

The following examples are provided for illustration only without limiting the scope of the present invention.

Comparative Example A

Effect of Zinc Oxide as an Antimicrobial Agent on Mold in Acrylic Latex Home Paints

The following experiments were conducted to test the effect of zinc oxide as an antifungal additive in latex household paints. A paint having the following composition is prepared.

Latex paint formulations containing zinc oxide:

ingredient Content (g) Water Hydroxyethyl Cellulosetamol 960 1 Ethylene Glycol Colloid 643 2 Triton CF-10 tripotassium tripolyphosphate 240.06.06.250.02.05.03.0 Pigment milled product: Titanium dioxide (rutile) aluminum magnesium silicate attapulgite clay zinc oxide aluminum silicate propylene glycol 500.0335.06.012.047.068.0 Let Down: Water Acrylic Latex Emulsion 60.0% Solid Colloid 643 Texanol 2.5% of hydroxyethyl cellulose ammonia in water 201.0760.06.022.080.00.5 Gross weight (g) 2349.7

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The paint is applied on a white pine substrate that has not been processed into two coatings with a brush to determine whether the coating supports mold growth on the coating. After being left outdoors for 4 months, growth is assessed as Grade 6 (medium growth) according to the method of ASTM D 3274-82.

Comparative Example B

Efficacy of Zinc Pyrithione in Acrylic Latex Home Paints

The following experiment is performed as another test for the effect of zinc oxide as an antifungal additive in latex household paints. A paint having the following composition is prepared.

Latex paint formulations containing zinc pyrithione but no zinc oxide:

ingredient Content (g) Water Hydroxyethyl Cellulosetamol 960 1 Ethylene Glycol Colloid 643 2 Triton CF-10 3 Potassium Tripolyphosphate 240.06.06.250.02.05.03.0 Pigment ground product: Titanium dioxide (rutile) aluminum magnesium silicate ether pulsite clay zinc pyrithione 48% dispersion aluminum silicate propylene glycol 500.0335.06.024.047.068.0 Let Down: Water Acrylic Latex Emulsion 60.0% Solid Colloid 643 Texanol 2.5% hydroxyethyl cellulose ammonia in water 201.0760.06.022.080.00.5 Gross weight (g) 2361.7

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The paint is applied on a white pine substrate that has not been processed into two coatings with a brush to determine whether the coating supports mold growth on the coating. After being left outdoors for 4 months, growth is assessed as Grade 8 (trace growth) according to the method of ASTM D 3274-82.

Example 1

Efficacy of Zinc Pyrithione and Zinc Oxide in Acrylic Latex Home Paints

The following experiments were conducted to test the efficacy of the combination of zinc oxide and zinc pyrithione as an antifungal additive formulation in latex household paints. A paint having the following composition is prepared.

Latex paint formulations containing zinc pyrithione and zinc oxide:

ingredient Content (g) Water Hydroxyethyl Cellulosetamol 960 1 Ethylene Glycol Colloid 643 2 Triton CF-10 tripotassium tripolyphosphate 240.06.06.250.02.05.03.0 Pigment milled product: Titanium dioxide (rutile) aluminum magnesium silicate at pearlite clay zinc pyrithione 48% dispersion zinc oxide aluminum silicate propylene glycol 500.0335.06.018.03.047.068.0 Let Down: Water Acrylic Latex Emulsion 60.0% Solid Colloid 643 Texanol 2.5% of hydroxyethyl cellulose ammonia in water 201.0760.06.022.080.00.5 Gross weight (g) 2361.7 Footnote 1. Anionic dispersants, products of the manufacturer (Rohm and Haas Company) 2. Defoamer, product of the manufacturer (Rhone-Poulenc Corp.) 3. Nonionic surfactant, product of Union Carbide Corp. 4. Fusing agent, product of Eastman Kodak Company

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The paint is applied on a white pine substrate that has not been processed into two coatings with a brush to determine whether the coating supports mold growth on the coating. After 4 months in the open air, growth is assessed to Grade 10 (no growth) according to ASTM D 3274-82.

All three paints of the three examples (Comparative Example A, Comparative Example B and Example 1) are used to paint three different cross sections of the same pine plank, minimizing the effect of using different pieces of wood. Example 1 suitably provides total resistance to the growth of mold on painted wood substrates, while the combination of zinc pyrithione and zinc oxide alone provides zinc oxide or zinc pyrithione (Comparative Example A and Comparative Runs). Example B) proved not to provide such resistance.

Example 2

Efficacy of zinc oxide in pyrithione-containing paint bases in preventing yellowing caused by UV exposure

The following experiments are conducted to test the efficacy of zinc oxide in the prevention, removal or reduction of yellowing caused by ultraviolet light in pyrithione containing paints.

A sample of an aqueous latex paint formulation containing zinc pyrithione (below) and two samples containing no zinc pyrithione were applied to the panel and exposed to a QUV vapor tester for 500 hours. Yellow index (“YI”) is measured at time 0 and 500 hours after exposure. The difference in YI for paints that do not contain zinc pyrithione after 500 hours of exposure is a 1.34 increase in yellow index. The difference for YI of paints containing 0.3% by weight of active zinc pyrithione is an increase of 3.68, indicating an increase in yellowing in exposure to UV with paints containing zinc pyrithione.

To each of these paint samples, 0.5% zinc oxide is added. The difference in YI for paints that do not contain zinc pyrithione is an increase of 0.37 after 500 hours of exposure in a QUV weather tester. The difference in YI for paints containing zinc pyrithione is 0.19 after 500 hours of exposure. These results demonstrate that zinc oxide prevents the occurrence of yellowing in paints containing zinc pyrithione when the paint is exposed to ultraviolet light.

Latex paint formulations containing pyrithione and latex paint formulations containing no pyrithione

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ingredient A (g) B (g) Water Hydroxyethyl Cellulosetamol 960 1 Ethylene Glycol Colloid 643 2 Nuosept 95 Potassium Tripolyphosphate 103.02.512.9018.002.0 3.00 2.0 103.02.512.918.00 2.0 3.00 2.0 Pigment milled product: Titanium dioxide (rutile) sodium potassium aluminum silicate attapulzite clay 200.0225.0 4.0 200.0225.0 4.0 Let down: 2.5% hydroxyethyl cellulose ammonia zinc pyrithione 48% dispersion in water acrylic latex emulsion 63.0% solid colloid 643 texanol 3 water 50.0 260.0 4.0 12.0 132.01.0 50.0 260.0 4.0 12.0 132.01.0 Gross weight (g) 1031.4 1037.4

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Both A and B added 200 g of 50% zinc oxide dispersant to prevent yellowing of paints containing zinc pyrithione and paints containing no zinc pyrithione as summarized in identification <139> and <140>. Compare.

Example 3

Efficacy of reduced amounts of zinc oxide in pyrithione-containing paint bases in preventing yellowing caused by UV exposure

The following experiments are conducted to determine whether lower concentrations of zinc oxide can be used to provide efficacy in avoiding, removing or reducing yellowing caused by ultraviolet light in pyrithione containing paints. According to the method of Example 2, two paints were prepared as follows.

ingredient A (g) B (g) Water Hydroxyethyl Cellulosetamol 960 1 Ethylene Glycol Colloid 643 2 Nuocept 95 Potassium Tripolyphosphate 103.02.512.9018.002.03.002.0 103.02.512.918.02.03.02.0 Pigment milled product: Titanium dioxide (rutile) sodium potassium aluminum silicate attapulzite clay zinc oxide 200.0225.0 4.0 2.0 200.0225.0 4.02.0 Let Down: Water Acrylic Latex Emulsion 63.0% Solid Colloid 643 Texanol 2.5% hydroxyethyl cellulose ammonia zinc pyrithione 48% dispersion in water 50.0 260.04.012.0132.01.06.0 50.0 260.04.012.0132.01.06.0 Gross weight (g) 1045.4 1049.4 Footnote 1. Anionic dispersants, products of the manufacturer (Rohm and Haas Company) 2. Defoamer, product of the manufacturer (Rhone-Poulenc Corp) 3. Fusing agent, product of Eastman Kodak Company

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The films from these paints are exposed to a continuous light QUV vapor tester using a UVA 340 bulb for 72 hours. The YI index is measured at this point and the difference in YI at time zero is:

YI Paint Sample A Paint Sample B 1.350.76

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The results provided in these experiments demonstrate that less than 0.2% zinc oxide in the formulation reduces yellowing caused by UV exposure. The addition of additional 0.4% zinc oxide to the total 0.6% by weight significantly reduces UV induced yellowing.

Example 4

Removal of blues caused by the presence of pyrithione and iron ions in paint bases

Efficacy of Zinc Oxide in Cleaning Blues Caused by the Presence of Iron Ions in Sodium Pyrithione-containing Paint Bases

The following experiments were conducted to test the effect of zinc oxide on the removal or reduction of blue caused by iron ions in pyrithione-containing paints.

Two samples, each weighing 150 g of the following aqueous (latex) paint formulation containing sodium pyrithione and zinc oxide, are placed in a plastic cup. The wooden snow depressor is then dipped into each sample and then dried to provide a control or "blank" comparison. Ferric chloride is then added to each sample so that the concentration of iron ions in each sample is 64 ppm. The snow tongue is coated to provide a reference for comparison. No discoloration occurs in the paint itself or in the anhydrous film of the painted snow tongue.

Latex paint formulations containing sodium pyrithione and zinc oxide ingredient Content (g) water 240.00 Hydroxyethyl cellulose 6.0 Tamor 850 ¹ 14.2 Ethylene glycol 50.0 Colloid 643 ² 2.0 Triton CF-10 ³ 5.0 40% active sodium pyrithione 3.0 Potassium Tripolyphosphate 3.0 Pigment Grinding: Titanium dioxide (rutile) 424.0 Aluminum magnesium silicate 228.0 Aterpulzite Clay 3.0 Zinc oxide 50.0 Aluminum silicate 100.0 Propylene glycol 68.0 Let Down: water 84.0 Acrylic Latex Emulsion 58.0% Solid 700.0 Colloid 643 6.0 Texanol ⁴ 18.6 2.5% hydroxyethyl cellulose in water 236.4 Gross weight (g) 2241.2 ¹ Anionic dispersant, product from Rohm and Haas Company ² Defoamer, product from Rhone-Poulence Corp. ³ Nonionic surfactant, product from Union Carbide Corp. ⁴ Fusing agent, Eastman Kodak Company's products

For comparison, two samples, each weighed at 150 g of the following aqueous (latex) paint formulation, containing sodium pyrithione but no zinc oxide, are placed in a paper cup. The wooden snow tongue is then immersed in each sample and then dried to provide a control or "blank" comparison. Ferric chloride is then added to each sample so that the concentration of iron ions in each sample is 64 ppm. The comparative coating on the snow tongue is visually observed to provide a basis for comparison. After 30 minutes a navy gray discoloration occurs in the paint itself and in the anhydrous film of the painted snow tongue.

Latex paint formulations containing sodium pyrithione and zinc oxide ingredient Content (g) water 240.00 Hydroxyethyl cellulose 6.0 Tamol 850 ⁵ 14.2 Ethylene glycol 50.0 Colloid 643 ⁶ 2.0 Triton CF-10 ⁷ 5.0 40% active sodium pyrithione 3.0 Potassium Tripolyphosphate 3.0 Pigment Grinding: Titanium dioxide (rutile) 424.0 Aluminum magnesium silicate 228.0 Aterpulzite Clay 3.0 Aluminum silicate 100.0 Propylene glycol 68.0 Let Down: water 84.0 Acrylic Latex Emulsion 58.0% Solid 700.0 Colloid 643 6.0 Texanol ⁸ 18.6 2.5% hydroxyethyl cellulose in water 236.4 Gross weight (g) 2191.2 ⁵ Anionic dispersants, products from Rohm and Haas Company ⁶ Defoamers, products from Rhone-Poulence Corp. ⁷ Nonionic surfactants, products from Union Carbide Corp. ⁸ Fusing agents, Eastman Kodak Company's products

Example 5

Removal of blues caused by the presence of pyrithione and iron ions in the paint

Efficacy of zinc oxide in removing blues caused by the presence of iron ions in zinc pyrithione-containing paints

In the presence of iron ions, zinc pyrithione containing paint compositions also tend to turn blue to gray at much slower rates than sodium pyrithione containing paint.

48% aqueous zinc pyrithione is added to a white paint containing 1.0% zinc oxide to bring the zinc pyrithione concentration to 3000 ppm in the sample. Ferric chloride is then added to bring the concentration of iron ions in the sample to 64 ppm. There is no discoloration of the paint after 1 month of standing.

No discoloration is detected when the composition is painted with very small amounts of steel or copper. This is surprising because it is expected that copper will discolor the paint and green will discolor the paint.

For comparison, 48% aqueous zinc pyrithione is added to a white paint that does not contain zinc oxide to bring the concentration of zinc pyrithione in the sample to 3000 ppm. Ferric chloride is then added to bring the concentration of iron ions in the sample to 64 ppm. If left for a week, the paint will turn blue.

Example 6

Discoloration removal method caused by the presence of pyrithione and iron ions in the aqueous coating

48% aqueous zinc pyrithione is added to the white paint sample to bring the concentration of zinc pyrithione in the sample to 3000 ppm. Ferric chloride is then added to bring the concentration of iron ions in the sample to 25 ppm. After two days, the paint will turn blue. At this point, 0.007% zinc sulfate (70 ppm) is added and the paint is mixed for 5 minutes. After a further 5 minutes, it is observed that the paint turns white and no more navy blue is detected. Zinc sulfate is added to the paint to remove the blue color formed by the addition of zinc pyrithione and ferric chloride.

Claims (29)

delete delete delete delete delete delete delete delete delete delete delete delete based on the total weight of the water medium, b) a vinyl medium, an alkyd resin, an epoxy resin, an acrylic resin, a polyurethane resin, a polyester resin and a base medium, a resin selected from the group consisting of combinations thereof, and c) an aqueous paint coating composition. D) zinc oxide selected from zinc oxide selected from a plurality of zinc oxides having a grade suitable for paint production, from 0.01 to 2.0% by weight of the pyrithione salt and d) 0.001 to 10% by weight based on the total weight of the aqueous paint coating composition. Aqueous paint coating compositions. The aqueous paint coating composition of claim 13, wherein the zinc oxide is present in an amount of 0.001 to 3% by weight, based on the total weight of the aqueous paint coating composition. The aqueous paint coating composition of claim 13, wherein the zinc oxide is present in an amount of from 0.02 to 0.5% by weight, based on the total weight of the aqueous paint coating composition. The aqueous paint coating composition of claim 13, wherein zinc oxide is present in an amount of 0.002 to 0.2% based on the total weight of the aqueous paint coating composition. The aqueous paint coating composition of claim 13 comprising a polymer latex. The process of claim 13 wherein iodopropynyl butylcarbamate ("IPBC"), n-octyl isothiazolin-one ("OIT"), methylene thiocyanate ("MTC"), thiocyanomethylthio benzothia Sol ("TCMTB"), thiazolyl benzimidazole ("TBZ"), benzimidazolyl carbamic acid methylester ("BCM"), triazoles, substituted triazines, dichlorophenyl dimethylurea and combinations thereof An aqueous paint coating composition further containing a co-biocide selected from the group. Pyrithione-containing paint coatings selected from the group consisting of zinc oxide, zinc hydroxide, zinc acetate, zinc sulfate, zinc chloride and combinations thereof in an amount of 0.001 to 10% by weight, based on the total weight of the pyrithione-containing paint coating composition. Pyrithione-containing paints comprising a resin selected from the group consisting of vinyl resins, alkyd resins, epoxy resins, acrylic resins, polyester resins, and combinations thereof, including incorporating an effective amount of a zinc compound used in the composition into the coating composition. A method of preventing the dry film of the coating composition from discoloring due to ultraviolet photolysis. The method of claim 19, wherein the zinc compound is used in an amount of 0.001 to 3% by weight, based on the total weight of the pyrithione-containing paint coating composition. The method of claim 19, wherein the zinc compound is used in an amount of 0.02 to 0.5% by weight, based on the total weight of the pyrithione-containing paint coating composition. delete An aqueous antimicrobial paint composition containing dissolved metal ions and pyrithiones selected from the group consisting of iron ions, copper ions and combinations thereof corresponds to a molar amount equal to or greater than the molar amount of metal ions dissolved in the composition. Discoloration of an aqueous antimicrobial paint composition comprising a resin selected from the group consisting of vinyl resins, alkyd resins, epoxy resins, acrylic resins, polyester resins, and combinations thereof, including contacting with 100 to 10,000 ppm zinc ions. How to remove it. 24. The method of claim 23, wherein the zinc ions are provided by incorporating a zinc compound selected from the group consisting of zinc oxide, zinc hydroxide, zinc acetate, zinc sulfate, zinc chloride and combinations thereof into the aqueous antimicrobial paint composition. delete water; Pyrithione salts or pyrithione acids; Organic base media selected from the group consisting of vinyl resins, alkyd resins, epoxy resins, acrylic resins, polyurethane resins, polyester resins, and combinations thereof; And zinc compounds present in the composition in an amount of 0.001 to 10% by weight, based on the total weight of the aqueous antimicrobial coating composition, protected against discoloration due to the presence of pyrithione and having antifungal efficacy. An aqueous antimicrobial coating composition for a substrate, characterized in that it is selected from the group consisting of aqueous paints, adhesives, cokes, sealants and combinations thereof. The coating composition of claim 26, wherein the zinc compound is present in an amount of 0.001% to 3% by weight based on the total weight of the aqueous antimicrobial coating composition. The substrate selected from the group consisting of wood, metal, plastic materials and mixed materials thereof is selected from the group consisting of water; Organic base media selected from the group consisting of vinyl resins, alkyd resins, epoxy resins, acrylic resins, polyurethane resins, polyester resins, and combinations thereof; Zinc compounds, which are selected from the group consisting of zinc oxide, zinc hydroxide, zinc acetate, zinc sulfate, zinc chloride and combinations thereof, in amounts of 0.001 to 10% by weight, based on the total weight of the coating composition; A coated substrate obtained by coating with a coating composition comprising pyrithione. The coated substrate of claim 28, wherein the zinc compound is present in the coating composition in an amount of 0.001 to 3% by weight, based on the total weight of the coating composition.